Sulfurization of planar MoO3 optical crystals: Enhanced Raman response and surface porosity

• Published in: Materials research bulletin Vol. 118; p. 110527
• Main Authors: Mohammadbeigi, Milad, Jamilpanah, Loghman, Rahmati, Bahareh, Mohseni, Seyed Majid
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2019
• Subjects: MoO3 crystals; Optical properties; Raman enhancement; Surface morphology; Raman enhancement; MoO3 crystals; Surface morphology; Optical properties
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2019.110527

[Display omitted] •Cm size MoO3 thin crystals are grown in a gradient of temperature.•Oxygen reduction and sulfurization has occurred at the surface of the crystals by sulfurization at different temperatures.•Favorable optical and morphological characters are observed in the crystals. Surface properties of planar crystals can be controlled for multi-purpose application. In this regards, we demonstrate a successful MoO3 planar crystal growth proposed for a wide tunability in surface characteristics. Such planar crystals are exposed systematically in sulfur gas at different temperatures. A large enhancement in Raman intensity was observed by sulfurization at 300 °C with the maximum of 46 times w.r.t. the non-sulfurized crystals due to surface oxygen vacancy. During sulfurization at higher temperatures, an MoS2 phase was observed to form at the surface of the crystals. Moreover, systematic imaging of surface evolution and optical response with increasing sulfurization temperature show systematic increase in surface porosity, decrease in optical band gap together with significant crystal color changes. Our findings can open pathways towards the growth of planar crystals at large scales with tunable characteristics for application in the fields of optics, sensor and energy.